Support bearings with elastic components are used specially in construction of helicopter rotors. Bearingless tail rotors of helicopters essentially comprise belts which are fastened to the rotor mast with a few bolts. The belts run inside of rotor blades, of which the ends on the side of the rotor mast comprise a control sleeve. The torsion of the rotor blades required for control purposes is attained through a torsion of the control sleeve. The belts give the tail rotor the required strength and they are elongated through the centrifugal force and bending moments arising during the rotation. A twisting of the belt by up to about 25.degree. takes place in connection with a rotating of the rotor blade by means of the control sleeve. In connection therewith a relative torsion between the control sleeve and the belt must be guaranteed and at the same time the sleeve must be supported in the transverse direction, i.e. in the flapping direction of the rotor. The connection between the belt and the control sleeve is provided by a support bearing, through which the belt is held in the control sleeve. Through the strong centrifugal and bending forces, which arise at this location of the rotor, the support bearings are exposed to high loads.
Typically, elastomer bearings are used as support bearings, of which the contact support components are made out of layers of titanium or steel plates, between which respectively an elastic material, for example rubber, is located. The belt is held in the middle of the control sleeve between oppositely lying elastomer bearing components. Due to the strong loads, special materials must be used for such type of elastomer sleeve support bearing and moreover, they must comprise a special structure to withstand the loads. These known elastomer bearings are therefore extremely costly, since they require a cost intensive development and manufacture. Moreover they comprise the disadvantage, that they change their stiffness and their material properties at different temperatures. The results are a reduced service life due to additional arising stresses.
To reduce manufacturing costs in the serial production of helicopter tail rotors, it was tried in new developments to substitute the elastomer bearings by twistable supports. Such a concept is described in "DEVELOPMENT OF BEARINGLESS TAIL ROTORS", Huber et al. Two day International Conference on Helicopter Yaw Control Concepts, Feb. 28, 1990, London. In such contact support components, likewise very high additional stresses arise in the contact support component in connection with a relative twisting of belt, however, which leads to premature material fatigue and increased cracking danger. The service life of conventional support bearings in the area of helicopter tail rotors is thus limited and can be held in a reasonable range only through expensive material compositions.